Convertible level



J. Hammfzfi CONVERTIBLE LEVEL Filed Aug. 27. 1926 2 Sheets-Sham l April 23, 1929. s. J. HEiNRlcH CONVERTIBLE LEVEL Filed Aug. 27. 1926 2 Sheets-Sheet Patented Apr. k23, 1929.

Unirse stares srnrnnu' J. limitaron, or Mawson. nnss INC., on Bossen,

ncnnsn'r'rs, nssien'oa fron. L.

CONVERTIBLE LEVEL.

Application lecl August 2*?, 1926. Serial' No. 131;@95.

This invention relates to engineers levels and more particularly to levels such as may be rapidly converted into transits. i

It is an object ot the present invention to reduce the cost el. production of ,iustri'u'nents oit this classv and at the saine time produce a sturdy, serviceable, and dun-ableA instrunient which. will withstand niore rough usage than higher priced instruments ot this cla A further object olffthe invention is to so construct and arrange the parts of the instrument that the bubble level is inclosed and protected, and a compact, simple, durableand inexpensive organization is provided.

Ano ther object of the invention to so arrange the vertical arc and its co-acting detent that so far vas theinitial horizontalr ad.- justnient of the telescope is concerned they are lixedwhile the bar and telescope are niade movable relatively thereto, to thereby ensure a perfect registration of the said detent and the co-actingnoteh or groove in the are.

It is a .further object of the invention 'to so arrange the detent that it may be instantly Controlled to permit of the conversionof the instrument from a level to a transit or vice versa, and to cause its pressure, when exerted on the are, to exert its power in the direction oit the rgreatest strength and least flexibility.

A still -further object of the'invention'is to provide sturdy lateral supports for the telescope to which end theprescnt arrangement oit the bar lends'itselt inasmuch as its trunnions project each side therefrom a coiniortable distance which enables the standards, l aving the supporting bearingsthere'or, to be suliieiently separated laterally toprovide bearings spaced more than ordinary in instruments ot' this type thereby,eliminating togreat extentythe possibility ot springing the horizontal axis ofthe instrument out of true. j i

Other objects of the invention will be fully understood lron'i a description oi the drawin and the' claiins hereinafter given..

Qt' the drawings: f

Figure llrepresents a lett side elevation oit the Convertible level. i f

Figure 2 is a`right side elevation of certain portions ot this level shown in Figure l.

Figure 3 is a sec V.onin the line 3 3 Figure 2 a portion of one of the trunnions being shown in elevation,

Figure 4l is a view showing a right side elevation olE the bar which supports the level andtelescope and to which. the vertical are is adj ustably attached..

lligure 5 is a detail showing a portion oitl compact and durable convertiblecompoundr` level. wherein a cap like base portion l() is arranged to support a levelling piece ll which niay be adjusted with relation thereto lby the screws l2 as usual in instruments of this general type. i L

The usual horizontal circle i3, indicated herein but not shownv indotail, is mountedk in a well known manner, and has a cover plate lll mounted to turn with a pin or'center, not showin 'to which is secured a base portionl having rupstanding therefrom the side traine orr siltandards' 16 and i7. i i

The said standa rds are arranged to provide dat itaced bearings i8 and l9`itor the' trunnions 20 oi a telescope-supperting tranne herein shown as a bar 2l, the said standards having their top porti ons separated by a saw out as at 22, the said. top portions oi' each of' the stand-r ards being inade adjustable towards and from each other by the screws 22X for the purpose et horizontally levelling the trunnions 2O and consequently the parts carried thereby.

The truunions 2O are prevented trombeing removed from the said bearings 18 and 19 by the straps 23 secured to the standards by screws 2li the holes for which in the straps being slightly elongated in practice to permit ot movement thereof when the trunnions are acljusted.

The bar 2l is oit novel struct-ure and is ar ranged to aid in accomplishing a plurality of new results viz it provides its own pivot truunions which extend laterally `there'lfron'i to such extent that vertical lateral twist is practically impossible even under unusual conditions of hard usage, a partial housing is provided r the bubble level 25 which could not be obtained in such a compact and siinplo manner it a pivot pinwere used intsead of the trunnions 20, and a longer radius'of vertical are having graduations thereon which are 'compact assembly, and to aid in the separated more than usual in levels ofthis class, andtl erefore more easily read, is made possible.

The bar 2l is also provided with cap bearings arranged to receive and firmly grip the telescope cylinder 27, and is arranged to provide a groove 28 centrally and longitudinally thereof for the reception of lthe said level to thereby permit of a more snug'and protection of the saidV level from harm or injury. Y

The said level is held to the said bar by the screws QQwhich are so arranged that the initial or subsequent adjustments necessary to true up the level and the iine of sight may be easily and rapidly mad'.k

The novel arrangement of the bar with its trunniens malte it possible to provide a sort of nest for the level 25, and l y so doing considerable valuablespaee is available which is utilized to increase tie radius of the 'ertical arc of graduated sector-30.

The said arc 30 is provided with a sogmental hub 3l which is i'iiachined to lit a like portion of one of the trunnions 2O against which it is arranged to be snugly held and between which relative movement may take place at the time of niaking the initial adjustmentbetween the arc and the said bar 2l.

lu the present instance theV are 30 is adjustably held to the bar 2l bythe capstan screws Six which providethe means for adjusting it with relation to the bar.

To normally retain the ltelescope 2T in position for use when the instrument is being used as a level a det-ent 32 is provided which takes theform of a bell crank lever pivoted to the standard 1G at 33, and having an upstanding socket 34e for the reception of a spring 35 which is arranged to bear against the arched portion of thestandard 17.

The-said detent `s shaped at its underside to enter a notch 36 in the 4inner periphery of the are 30 to normally yieldingly lock the said arc, and conse( uentl 1 the bar il and the parts i il i carried thereby', iu position for use as a level.

It will be understood that the arrangement Y ofthe detent 32 and notch oo with which it engages is such that if need be the said detent ymay be disengaged from thenotch by the use of slight upward or downward pressure on the end of the telescope 27 which will cause the top edges of the notch to cam the detent upwardly against the action of the spring whereupon it will ride upon the smooth inner periphery of the arc and provide frictional means to retain the are in any angular position in which it finds itself when at rest.

then the .instrument is to be used as a transit it is preferred to so arrange the detent that itmay be put out of engaging vcontact with the arc, and to that end the shortlarm 37 thereof is bored to receive a screw 38 having a smooth shank portion passing through the bore or hole, and a threaded endto engage a Y threaded hole in the base portion l5 as seen in left hand and coarse so that by turning the screw to the right the are or notch engaging portion of the detent will be forced into engagement with the arc by the spring 35, and turning' the screw to the left will force it upwardly and out of engaging position. A stop 39 ertendin from the head of the screw 38 is arra in each direction of movement of the screw so tl .t undue movement' thereof prohibited.

Having described the invention l claim:

l. A convertible level comprising a telescope; a level a frame upon which said telescope and level are mounted to swing, said J2rame having bearings arranged to encircle said telescope, and having trunnions laterally extending from the sides thereof7 and a de.- `pression longitudinally thereof for the reception of said level whereby said level is conipactly assembled with said frame and protected thereby; a vertical are having ends adjustably secured to said frame, and having a hub portion arranged to contact with and swing about a trunnion; and a detent arranged to normally yieldingly lock said are and consequently said telescope, and level in a given angular position.

25A convertible level comprising a telescope; a level; a frame upon which said telescopeand level are mounted to be swung; a vertical are adjustably secured to said frame; and a detent for said are comprising a bell crank lever; means to normally retain said detent and are in Yopera-'tive relationship; and means to retain said detent out of operative relationship with respect to said are.

3. A convertible level comprising a telescope.; a level; a frame upon which said telescope and level are mounted to swing in a vertical plane; a vertical are adjustably secured to said frame; a bell crank lever arranged to move radially of said arc and to bear against the inner edge thereof; a spring arranged to normally retain said bell crank in contact with said arc; and a screw arranged to move said bell crank out of Contact with said are.

e. A convertible level comprising a base having standards upwardly projecting therefrom, said standards having bearings at the upper ends thereof; a. telescope-supporting frame interposed between said standards and having a pivot laterallyextended from each side thereof arranged to be pivotally supported in said bearings, said bearings being separated a distance approximately twice the width of said frame whereby a sturdy support against twist is afforded saidy frame; a

o d to eno'ao'e theto i side of the base l5 said frame; and means to retain said frame in. one of various angular positions thereof.

5. The combination With the telescopesupporting frame provided at opposite sides thereof With trunnions, of a vertically dis.- posed graduated sector made With a hub segment litting against one of said trunnions, and means Connecting said sector with said traine so as to hold said segment litted against said trunnion.

6. In an instrument of the character deseribed, the combination with the telescopesupporting iii-aine provided at opposite sides thereof with trunnions, of a vertically disposed graduated :sector made with a graduated arcuate bar and with a hub segment litting against one of said trunnionsgscrews adjustably connecting the opposite ends of said sector with said frame so as to normally hold said segment lixedly against said trunnion, and a spring pressed detent engaging the periphery oit said arcuate bar in all positions of the latter to yieldingly hold. said iframe in adjusted position.

va bubble level disposed longitudinally between said iiraine and said'telescope and also between said trunnions; a vertically disposed graduated sector having a hub portion litting against one of said trunnions; means adjustably connecting said sector with said frame so as to normally hold said hub portion fixedly against said trunnion, said connecting means being operable to rotate said sector on said trunnion.; a yoke base having bearings in which said triiinnions are journaled, and a spring pressed detent on said yoke base engaging ysaid sector to yieldingly hold said frame in horizontal position.

Signed by me at Boston7 Massachusetts7 this 26th day of August 1926.

STEPHEN J. HEINRICH. 

